Re: LATERAL quals revisited

Some time ago, I wrote:
> I've been studying the bug reported at
> http://www.postgresql.org/message-id/20130617235236.GA1636@jeremyevans.local
> ...
> After some contemplation, I think that the most practical way to fix
> this is for deconstruct_recurse and distribute_qual_to_rels to
> effectively move such a qual to the place where it logically belongs;
> that is, rather than processing it when we look at the lower WHERE
> clause, set it aside for a moment and then add it back when looking at
> the ON clause of the appropriate outer join. This should be reasonably
> easy to do by keeping a list of "postponed lateral clauses" while we're
> scanning the join tree.

Here's a draft patch for this. The comments need a bit more work
probably, but barring objection I want to push this in before this
afternoon's 9.3rc1 wrap.

regards, tom lane